Can someone explain this circuit to me?

I am very new to this, but I am trying to understand the wiring diagram at this site:

http://sishchess.blogspot.com/p/building-sish-board-tutorial.html

Most of the tutorials I've read connect a to power, through a resistor to a pin and the button then to ground. It looks like the circuits here would simply pass from one pin to another with power or ground. How does this work? Would you simply write to one pin and read another to see if the message was received to see if the button is pushed? If that was the case, I guess you would continuously write to one bank of pins (the letters for example) and read the other bank and based on which message is delivered and where it is received then you would no which button in the matrix was pushed.

It's called an 8x8 matrix keyboard.
Here is a link how it works and how it can be read out: http://pcbheaven.com/wikipages/How_Key_Matrices_Works/

Regards,
Paul

Thanks.. that's kind of what I envisioned but this explanation was very clear.

Normally you should use the Keypad library for this type of switch matrix circuit.

https://www.pjrc.com/teensy/td_libs_Keypad.html

The Keypad library is well tested and easy to use.